Employees of the federal Department of Fisheries and Oceans were told Wednesday their employer will soon be significantly smaller, and responsible for fewer things.

DFO also warned its workers that some of them will definitely not be working there once the department completes a $56.8-million budget-cutting plan by 2014.

"More savings are expected in the future," said a letter signed by Deputy Minister Claire Dansereau and two other top officials.

The letter and supporting documents, which were obtained by CBC News, say reductions are part of a "dynamic change agenda," and will apply broadly to services that include the Canadian Coast Guard.

The changes incorporate cuts that have already been announced, including a controversial move to shut down the Maritime Rescue Sub Centre in St. John's and a similar office in Quebec, with service to be provided by staff in other provinces.

A background note says that DFO is "winding down or shedding non-core programs," as part of "key transformations" intended to render a more modern style of managing fish stocks, ecosystems, aquaculture and vessels.

The documents, obtained Wednesday by CBC News, do not include specific details on job losses, although the memo said DFO will attempt to mitigate cuts through attrition and new assignments.

"We will be phasing-in these and other change initiatives over three years to allow time for the Department, employees and stakeholders to adjust," the employee letter said.

"We are confident that the cumulative effects of these measures over the long-term will be positive, helping us to improve the quality, relevance and effectiveness of the Department's programs and services."

DFO, which has sustained deep cuts to its science program over the last two decades, is preparing for further cuts in that area. Senior managers will be "finding efficiencies and simplifying how science is managed."

The department said it is moving to "an ecosystems approach to science."

The department also intends to make greater use of technologies, including moving to a web-based renewal and payment system for fishing licences.